THERE's a line in cricket sledging that Michael Clarke, with his implied threats of physical harm, actually didn't cross - on the other side of that line are racism and other players' mothers.

Discussion is hot this morning about whether Clarke's warning to England player Jimmy Anderson to "get ready for a broken f*cking arm" was conduct unbecoming of the Australian Cricket Captain, a job Clarke's wife Kyly thinks is: "the second most important job in Australia."

It doesn't sound good in isolation does it. At the pub that kind of talk would get someone like Clarke into a very sticky situation.

But Clarke said: "Through my career I heard a lot worse said on the field than any of the Australian players or England players have said throughout this Test."

He's right.

Sledging might not be something you want your eight-year-old cricket-tragic son to aspire to, but a lot worse has been said Clarke's Gabba outburst last night.

When it goes too far sledging is an excuse to air players' some players' basest racism or lack of respect for women.

Like when Harbhajan Singh called Andrew Symonds a "monkey". Singh was fined $3000 for general abuse but charges of racial abuse were dropped and a three-match ban overturned on appeal.

The nasty affair gives Clarke's sledging some perspective.

The AFL has drawn the line at sledging about people's mothers, but in cricket wives have been fair game for years, most famously when Glenn McGrath asked Eddo Brandes how come he was so fat and Brandes replied "because every time I f*ck your wife she gives me a biscuit".

News.com.au's Privacy Policy includes important information about our collection, use and disclosure of your personal information (including to provide you with targeted content and advertising based on your online activities). It explains that if you do not provide us with information we have requested from you, we may not be able to provide you with the goods and services you require. It also explains how you can access or seek correction of your personal information, how you can complain about a breach of the Australian Privacy Principles and how we will deal with a complaint of that nature.